Method osi and apparatus eos ramming sand into molds



W. S. SUTTON.

METHOD OF AND APPARATUS FOR RAMMING SAND INTO MOLDS. APPLICATION FILED FEB. 21. 1921.

1 ,426, 6 1 Patented Aug. 22, 1922.

UNITED STATES PATENT OFFICE.

WILLIAM S. SUTTON, OF ROCKFORD, ILLINOIS.

Application filed February 21, 1921.

To all whom. it may concern Be it known that I, VVILLIAL'L' S. Su'r'ron, a citizen of the United States, residing at Rockford, in the county of Winnebago and State of Illinois, have invented new and use ful Improvements in M thods of and Apparatus lor Hamming Sand into Molds, of which the following is a specification.

This invention relates in general to tonndry equipment, and has more particular reference to a method of and apparatus for ramming molding sand into molds.

Foundry practice, as customarily carried on, involves a great deal of heavy manual labor in shoveling the molding sand into the molds and ramming or tamping it tightly in the molds around the patterns, and also involves considerable expert skill, particularly in the tamping operations to insure that the sand is snugly packed around all the irregularities of the pattern.

The primary purpose of my present invention is to provide a method and appara tus for simultaneously filling the mold with sand and firmly tamping or ramming it into the mold so that the sand is snugly packed around all of the irregularities of the pattern, thus eliminating not only the laborious task of shoveling the sand into the mold, but also the labor of tamping or ramming the sand after it has been placed in the mold, the present invention being designed to automatically deliver the sand to and ram it into the mold without the employment of any manual. labor other than that oi moving a delivery nozzle about so that the sand will be delivered to and packed into all portions of the mold.

Another object of my invention is to provide a method which will insure uniformity in the density of the sand in the mold around the pattern and to provide an apparatus tor carrying out the method which will be simple in construction, cheap to manutacture, easy to install, and one which will be eitticient and reliable in operation, so that it will not only eliminate the manual labor heretofore considered necessary, but will also speed up the filling and ramming of the molds so that the time required in performing these operations is very materially reduced.

Other objects and many of the inherent advantages of this invention will be readily appreciated by those skilled in the art as the same becomes better understood by reference to the following description when Specification of Letters Patent.

Patented Aug. 22, 1922.

Serial No. 446,708.

considered in connection with the accompanying drawing, the single figure of which illustrates in vertical section one novel and perfected form of apparatus for carryin out my improved method. 6

Referring now to the drawings more in detail, reference character 5 indicates the bin 111 wh ch the moulding sand is contained attcr being properly mixed and prepared, and rrom which it is elevated by the conveyor 6 to a smaller conveyer 7. The convevei 6 is preferably of the endless bucket type, and dehvers the material after being elevated, to the belt conveyor 7 equipped with cleats or cross bars 8. It is to be understood that the conveyors 6 and 7 may be of any other preferred construction and may be driven in any suitable manner. The conveyor." 7 delivers the sand which it receives from the conveyor 6 into the hopper 9, from which it is then delivered to the flaredend 11 oi: a sand conduit 12.

For the purpose of delivering the sand from the hopper 9 only when and in such quantities as may be required, a manually controlled feeding roller 13 is employed, which is driven by means of a chain 14- from a motor 15, said motor being preferably of the electric type adapted to be controlled by a pull cord or the like 16. This pull cord which actuates the controlling switch of the motor, is preferably trained over nulleys 17 to position. the hand pull 18 at its lower and within convenient reach of the operator standing near the mold. It will thus be manitest that by manipulation of the hand pull, the delivery of sand from the hopper 9 may me started and stopped at will. For the purpose of increasing the vel ocity of the sand travelin through the conduit to point considerably higher than that which would be imparted to it by gravity, my invention contemplates the employment of compressed air delivered into the couduit longitudinally thereof, and in the di rection of travel of the sand whereby the velocity of the sand is very materially increased. For this purpose, I have provided a pipe 19 extending downwardly into the flared end or mouth 11 of the conduit through which the air under pressure is de livered within the stream of flowing sand, producing an injector blower action which materially accelerates the speed of the sand. The compressed air may be received from any suitable source of supply, but in the present instance, I have shown a rotary has compressor 21 of any preferred type driven from a motor 22 through a belt 23, or from any other suitable source of power.

The sand travels downwardly through the conduit under the influence of gravity, greatly accelerated by the action of the compressed air, and the velocity attained is sufficient to cause its delivery into a mold with such force that it will be tightly packed therein, but in order to prevent a blast action which would scatter the sand over and around the mold, it is desirable to relieve the sand of air pressurebefore it enters the.

mold. With this end in view, I have made provision for withdrawing the air before it reaches the mold by permitting it to escape form the conduit and separate itself from the stream of flowing sand. The conduit 12, therefore, is made perforate throughout a portion of its length, indicated by reference character 24:, and to augment the expansion and separation of the air from the sand, this perforated portion is surrounded by a funnel-shaped expander 25 open at its lower end, as shown, the air being adapted to escape through the perforations in the conduit and flow downwardly and outwardly around the lower edge of the expander. To further facilitate the escape of the air, a portion of the conduit is removed, as indicated at 26, so that direct communication is established with a surrounding expansion chamber 27 having a funnel-shaped bottom 28 to which a pipe 29 forming a continuation of the conduit, is secured, and into which the sand issuing from the perforated portion of the conduit is directly discharged. The greater volume of the compressed air escapes through the perforated portion of the conduit, as previously explained, but the fu ther relief afforded by the break in the conduit permits a complete relief of air pres sure on the stream of sand without diminishing the velocity of the sand which continues to travel at high speed downwardly through the conduit.

While the air thus escaping under pressure might be permitted to escape to atmos phere, I prefer to confine it and to further insure the complete relief of the pressure by producing a slight vacuum in the expansion chamber 27. This result is accomplished by connecting the chamber through a pipe 31 with the intake side of the compressor 21 so that the air is withdrawn from this chamber and recirculated through the delivery pipe 19. To obviate the production of either excessive vacuum or excessive pressure in the expansion chamber openings to atmosphere are provided at the connection between the bottom 28 and the pipe 29, and an up wardly inclined funnel-shaped flange disposed beneath said openings prevents the escape of sand through the openings from the conduit, as will be apparent from the drawings. In order to protect the compressor against action of sand particles which might .be drawn into it along with theair, a cylindrical screen 32 is interposed in the chamber 27, which serves to screen the air of the sand particles, which particles drop into the conically-shaped bottom 28 of the chamber and are drawn on downwardly into the conduit .by the stream of sand flowing therethrough at high velocity. V

The conduit below the chamber preferably comprises telescopic sections and 3a, the section 84 being equipped with a handle 35 by which it may be raised and lowered, and this section being counterbalanced by weights 36 to render it easy of manipulation by the operator. The discharge end of the conduit comprises a flexible hose or nozzle 37, through which the sand is delivered directly into mold 88 positioned beneath the apparatus. The flexibility of the nozzle 3? enables the operator to move it about so that sand may bedelivered to all portions of the mold. For purposes of illustration, I have shown a pattern 39 in the mold, and the sand packed in the mold around the pattern is indicated by reference character 41.

In order that the pressure of the air delivered through the pipe 19 may be observed, I prefer to equip the apparatus with a pressure gauge 42 connected by a pipe 43 with a chamber iel interposed in the pipe 19, and since the pressure need be only intermittently observed, I prefer to equip the pipe adjacent the chamber lt with a valve 45, which may be opened to permit the pressure to register in the gauge l2 whenever desired, by means of a pull cord 46 equipped with a hand pull a? in convenient reach of theoporator. i

It will be apparent from the foregoing that by my improved method, the sand is first elevated, then delivered under the control of the operator into a conduit in which its speed is accelerated to a velocity suffcient to pack the sand firmly in the mold into which it is delivered from the conduitthrough a flexible nozzle, and that the air pressure is withdrawn from the sand without diminishing the velocity of the sand so that no air blast effect or scattering of the sand from the mold can occur.

It should be manifest also that the apparatus disclosed for carrying my method into effect is capable of considerable modification, and obviously, it might be constructed to simultaneously fill two molds where large capacities are required, and other changes might be resorted to without departing from the essence of the invention, as defined in the following claims.

I claim:

1. The herein described method which consists in flowing a stream of mingled pressure fluid and material through a conduit,

positively withdrawing pressure fluid from the stream before it discharges from the conduit, and permitting the material free from pressure fluid to flow by momentum through the conduit and discharge therefrom.

2. The herein described method which consists in flowing a stream of mingled pressure fluid and material through a conduit, applying suction to the mingled stream for positively withdrawing pressure fluid therefrom, and permitting the material free from pressure fluid to flow by momentum through the conduit and discharge therefrom.

3. The herein described method which consists in taking a conduit having an inlet and an outlet, feeding material continuously to the inlet, also feeding pressure fluid to the conduit and producing a mingled stream of material and pressure fluid flowing through the conduit, positively withdrawing pressure fluid from the conduit intermediate the inlet and outlet thereof, and permitting the material free from pressure fluid to flow by momentum through the conduit and discharge through the outlet thereof.

4. The herein described method, which consists in flowing a stream of mingled material and pressure fluid through a conduit having an outlet, forcibly withdrawing pressure fluid from the stream and leading it back into the conduit in rear of the point of withdrawal, and permitting the material free from pressure fluid to flow by momentum through the conduit and discharge therefrom.

5. The method of ramming sand into molds which consists in, subjecting a quan tity of sand to a stream of air under pressure to impart a high velocity to said sand, directing the sand at high velocity into a mold, and withdrawing the air pressure from the sand before'it reaches the mold.

6. The method of rammingsand into molds which consists in, directing a stream of sand into a mold, imparting a high velocity to said stream by subjecting the same to air pressure delivered in the direction of travel of the stream, and withdrawing the air pressure from said stream prior to its delivery into the mold.

7. The method of ramming sand into molds which consists in, delivering a quantity of sand to a conduit, delivering air under pressure into said conduit to accelerate the speed of the sand therein, and positively relieving the sand of said air pressure before the delivery end of the conduit is reached.

8. In a sand ramming apparatus, the combination of a compressed air nozzle, means for delivering sand adjacent to said nozzle, a separating chamber, a perforated conduit through which said air and sand are de livered to the chamber and a funnel-shaped expansion member surrounding said conduit within said chamber, whereby the air is.

gradually expanded without deflecting the sand from its course.

9. In a sand ramming apparatus, the combination of a compressed air nozzle, means for delivering sand adjacent to said nozzle whereby the velocity of said sand is increased, means for positively withdrawing the compressed air from the sand, and a conduit adapted to receive the sand after the air has been separated therefrom, said conduit being provided with a flexible delivery end for delivering the sand to any desired portion of a mold.

10. In a sand ramming apparatus, the combination of a sand conduit including a portion having perforated walls, means for delivering sand to said conduit, means for subjecting said sand to the action of air pressure delivered in the direction of travel of sand through the conduit, and means for withdrawing said air through the perfo rated walls of said conduit.

11. In a sand ramming apparatus, the

combination of a sand conduit, means for supplyng sand thereto, pneumatic means for accelerating the speed of the sand in said conduit, a flexible delivery nozzle whereby said sand under high velocity may be directed to any part of a mold and means whereby the sand is positively relieved of pneumatic pressure prior to its delivery from said nozzle.

12. In a sand ramming apparatus, the combination of a sand conduit, means for supplying sand thereto, means for delivering compressed air to said conduit in the direction of travel of the sand therethrough, and means for withdrawing the air from said conduit before the sand is delivered therefrom.

13. In a sand ramming apparatus, the combination of a sand conduit, means for delivering sand thereto, a pipe for deliveringair under pressure into the conduit in the direction of flow of the sand to increase the velocity of said sand, means for withdrawing the air under pressure from said conduit, a screen through which the withdrawn air passes, and a flexible discharge nozzle for said conduit through which the sand may be delivered to any part of the mold.

14.111 a sand ramming apparatus, the combination of a sand conduit perforated throughout a portion of its length, means for delivering sand thereto, a pipe for delivering air under pressure into said conduit, a funnel-shaped expansion member sudrounding the perforated portion of said conduit, an expansion chamber surrounding said member, screens in said chamber, means for withdrawing the air through said screens, and a flexible delivery nozzle.

WILLIAM S. SUTTON. 

